1. Field of the Invention
The present invention relates to an intelligent car battery-charging cable device, and more particularly to an intelligent car battery-charging cable device including multiple groups of circuits which are connected to indicate the powered on state and achieve an idlenessproof effect. The charging cable device further includes an cooperative protection device for ensuring triggering so that the charging cable device has an intelligent idlenessproof protection function. Only when all the positive and negative electrodes of both the normal ends and failing power end are correctly connected, the circuit between the normal and failing power ends is closed for charging operation. In case of incorrect connection, the circuit between the normal end and failing power ends remains open so as to avoid short circuit and a warning signal indicating the incorrect connection is emitted for a user to remove the incorrect connection.
2. Description of the Related Art
FIG. 1 shows the conventional power cables for connecting the battery of a car to an external power supply. Two ends of two parallel cables 5 are respectively equipped with clips 51, 52, 53, 54. The two clips 51, 52 on one side of the two cables 5 are used to respectively clip two electrodes of the external normal power supply, while the two clips 53, 54 on the other side of the two cables 5 are used to respectively and correspondingly clip the positive and negative electrode of the failing battery for charging the battery. By such measure, the correct connection positions are not clearly indicated. Therefore, in the case that the application environment lacks sufficient illumination or the user is not fully aware of electrical properties, frequently the positive and negative electrodes are reversely connected to cause damage to the normal circuit system.
FIG. 2 shows a prior DC power connecting cable device of the applicant. The DC power connecting cable device has a function of idlenessproof indication for eliminating the problem of the conventional power cables. A light emitting diode (LED) 61 is forwardly connected between the positive and negative power cables 5. The clips at the normal power end are used to clip the positive and negative electrodes of the normal power source, whereby the LED 61 has a forward bias and emits light so as to indicate the correct clipping state of the cable clips at the normal power end. In addition, at the normal power end, another LED 62 is serially connected with a test conductive plate 7. When the test conductive plate 7 contacts with the negative electrode of the failing power source, a forward bias is produced to make the LED 62 emit light so as to detect the negative electrode of the failing power end. Therefore, the incorrect connection of the positive and negative terminals of the power cables can be avoided. Such structure can achieve an idlenessproof function. However, the operation of such device is troublesome and the device lacks protective design for avoiding damage caused by an incorrect connection. In order to eliminate the shortcoming of such device, the applicant developed an improved device as shown in FIG. 3. In the improved device, a breaker (not shown) is disposed between the normal and failing power ends of the positive and negative power cables 5. Two LEDs 63, 64 on two sides of the breaker are forwardly connected with the positive and negative electrodes of two ends, whereby the LED on one side can have forward bias to emit light for indicating the correct clipping state of the cable clips at the normal power end, while the LED on the other side can emit light to indicate the correct clipping state of the cable clips at the failing power end. In case of incorrect connection at the failing power end, the breaker can open the circuit of the power cables at the normal and failing power ends so as to protect the power sources from being damaged due to incorrect connection. In addition, a buzzer 8 is backward connected between the positive and negative power cables at the failing power end for emitting a warning sound in the case of incorrect connection at the failing power end. Such device provides a protection function and a warning function. However, all the above power cable devices have normally closed current circuits. The two types of connection circuits of FIGS. 1 and 2 cannot provide any protection in case of incorrect connection. This may lead to short circuit and damage the power sources at two ends. The improved device of FIG. 3 has a breaker for opening the circuit in case of short circuit so as to protect the power sources and activate an alarm to emit warning sound. However, the improved device can cut off the current only when detecting the short circuit so as to minimize the damage of the power sources at two ends. This still pertains to a passive protection circuit so that the power sources at two ends will still be affected by the instantaneous short circuit. Furthermore, in case that the breaker is damaged or malfunctions, the straight short circuit or poor contact may even seriously damage the power sources at two ends.